On Fri, 2 Jul 1999 16:19:07 -0700 (MST), you wrote: > Similar spectra must exist for various common obscurations > suspended/dissolved in water; it might even be worth looking at a > tunable-wavelength imager to maximize penetration for a given set of > conditions. Not all poor-visibility water is created > spectroscopically equal! Yeah, it's called sound :-) Later, Jon